1. Field of the Invention
The invention concerns a storage case for a disc-shaped information carrier with a clearance in the central area, for an optically readable digital audio-disc otherwise known as a compact disc or CD. In particular, the storage case has a receptacle member and a base member, which is substantially fitted to the outline of the disc and inserted into the receptacle member. The base member is provided with a central retaining element which passes through the clearance of the disc and has spring-catches developed as a locking element which overlap with a thickening of the inner edge of the clearance of the disc pointing radially outwards.
2. Description of the Related Art
Storage cases of this type have cap-like spring-catches which are disposed as retaining elements which can be connected with the clearance of the disc. This connection is frequently so tight that the disc can only be removed from the case with some difficulty. As the spring-catches have end members directed radially inwards, at times it is possible to press on these ends with the index finger and thereby to bend back at least a part of the spring-catch, such that the click-stop connection between the retaining element formed by the spring-catches and the clearance of the disc, even if it is not fully released, is nevertheless loosened and it is possible to remove the disc.
In DE-C2-34 25 579 a storage case of the foregoing type is described, for which removal is made easier in that the spring-catches towards the inside have a fixed attachment inwards to a pressure plate. It is possible for the attachment to be elastically produced such that it can be deformed such that at the time of a deformation of the pressure plate, by means of pressure applied with a finger, the spring-catches are arched inwards and therefore the click-stop connection between a retaining element and the clearance of the disc are released. Removal of the disc should be facilitated in that spring elements are provided which are depressed by the inserted disc and when the pressure plate is pressed down, these spring elements push upwards from the back of the disc through the click-stop of the spring-catches. As, however, the base members of this type of case are mass-produced products and allowable variation can be present throughout, an insufficient or loose locking between a retaining element and the disc is sometimes produced. The arrangement of these types of spring elements have the disadvantage that the spring elements release the disc from the retaining element without pressure on the pressure plate, so that the precise purpose of a safe retention of the disc is not guaranteed.
A traditional kind of storage case is furthermore known from DE-A1-37 15 187, in which a spider-like body with arms bent back upwards is inserted into the central boring and the slots in the base member which partition the spring-catches. The arms being developed so that the ends of the arms come upwards out of the slots through a pressure on the body and should lift out the inserted disc. This storage case has the disadvantage that when there is a pressure on the body, the whole force must be applied in overcoming the force of retention exerted by the arms. As the arms can be deformed because of the way they are fashioned, the transmissible force is not sufficient in some cases where there is a large retaining force to overcome the device for locking the spring-catches.